Patients in the intervention group significantly improved their diet quality and physical activity levels from baseline, compared with those in usual care.

Many women who undergo treatment for breast cancer experience unwanted side effects, including fatigue, weight gain, joint pain, and hot flashes, explains Tara Sanft, MD. “In the post-treatment phase, we would often hear women say they wish they had been able to do more during treatment to prevent these effects from occurring,” she says. “For women treated with chemotherapy, side effects can interfere with completing the treatment as planned. For patients being treated with endocrine therapy, side effects contribute to early discontinuation and nonadherence.”

Addressing this issue, Dr. Sanft and colleagues conducted a randomized trial of an exercise and nutrition intervention on relative dose intensity and pathologic complete response (pCR). Their findings were published in the Journal of Clinical Oncology.

Dr. Sanft and colleagues assessed a healthy diet and exercise intervention given to patients with breast cancer immediately after diagnosis, administered during chemotherapy treatment, to see if it could have an impact on side effects and improve chemotherapy completion rates or adherence to endocrine therapy at 1 and 2 years.

Registered Dietitians Certified in Oncology Nutrition Conducted the Study

“We enrolled women with early-stage breast cancer who were going to be treated with chemotherapy but were not already adhering to a healthy diet and exercise program,” she says. “We randomized these women to a healthy lifestyle intervention versus usual care.”

The study was conducted by trained registered dietitians, certified specialists in oncology nutrition with exercise science training, she explained. The intervention consisted of 16 sessions over the course of 1 year, delivered either in person or virtually. The usual care group was referred to a survivorship clinic, a standard of care at Yale School of Medicine.

“We observed that women in the intervention group significantly improved their diet quality and physical activity levels from baseline, compared with usual care,” Dr. Sanft says. “This is important because eligible patients needed to not be meeting recommended guidelines to enroll, indicating that even sedentary patients with a suboptimal diet quality can adopt healthy behaviors during breast cancer treatment.”

“Never Too Late” to Recommend Adopting Healthy Diet & Exercise Patterns

Two key findings stood out, according to Dr. Sanft. “The first is that women in the intervention group significantly increased their physical activity, including strength training, and their diet quality during chemotherapy compared with usual care,” she says. The second is that some of the changes were small, yet all contribute to a healthy eating and activity pattern. “This indicates that it is never too late to recommend adopting healthy diet and exercise patterns and even small changes can contribute to the overall health of an individual,” Dr. Sanft points out (Table).

The study group also observed high rates of chemotherapy completion in both groups, with similar rates of dose reductions and delays. “When we looked at a subset of women who underwent neoadjuvant treatment, however, we found a significantly higher rate of pCR in those in the intervention group compared with those in usual care,” she notes. “These findings are surprising, since both groups completed chemotherapy at similar rates, suggesting something other than treatment may be mediating the response. Therefore, these findings need to be studied further.”

For future research, the study team would like to see oncologists explore physical activity and healthy eating patterns in patients as a part of a comprehensive assessment. Dr. Sanft says, “Though chemotherapy completion rates were high in both groups, the higher pCR rates are exciting because women who achieve a pCR typically go on to have an excellent prognosis. Since diet and exercise improvements have very little downside, it is a recommendation that has many benefits in addition to impacting these outcomes.”